Y is a series of Recommendations (standards) from the Standardization Sector the International Telecommunication Union (ITU-T), the description of the Y series is: "Global information infrastructure, Internet protocol aspects and next-generation networks".
| Specification Range | Specification Type |
|---|---|
| GLOBAL INFORMATION INFRASTRUCTURE | |
| Y.100–Y.199 | General |
| Y.200–Y.299 | Services, applications and middleware |
| Y.300–Y.399 | Network aspects |
| Y.400–Y.499 | Interfaces and protocols |
| Y.500–Y.599 | Numbering, addressing and naming |
| Y.600–Y.699 | Operation, administration and maintenance |
| Y.700–Y.799 | Security |
| Y.800–Y.899 | Performances |
| INTERNET PROTOCOL ASPECTS | |
| Y.1000–Y.1099 | General |
| Y.1100–Y.1199 | Services and applications |
| Y.1200–Y.1299 | Architecture, access, network capabilities and resource management |
| Y.1300–Y.1399 | Transport |
| Y.1400–Y.1499 | Interworking |
| Y.1500–Y.1599 | Quality of service and network performance |
| Y.1600–Y.1699 | Signalling |
| Y.1700–Y.1799 | Operation, administration and maintenance |
| Y.1800–Y.1899 | Charging |
| NEXT GENERATION NETWORKS | |
| Y.2000–Y.2099 | Frameworks and functional architecture models |
| Y.2100–Y.2199 | Quality of Service and performance |
| Y.2200–Y.2249 | Service aspects: Service capabilities and service architecture |
| Y.2250–Y.2299 | Service aspects: Interoperability of services and networks in NGN |
| Y.2300–Y.2399 | Numbering, naming and addressing |
| Y.2400–Y.2499 | Network management |
| Y.2500–Y.2599 | Network control architectures and protocols |
| Y.2700–Y.2799 | Security |
| Y.2800–Y.2899 | Generalized mobility |